The present invention relates to an axle bolt to rotatably mount a wheel or the like to an axle, which includes means for lubricating the bearings which rotatably support the wheel.
There are a number of arrangements for lubricating bearings for wheels or other rotating parts, but most are complicated and require structures other than that needed to accomplish the rotatable movement between a shaft and the wheel or the like.
Previous axle bolts have been provided which include an axle passage for the necessary lubricant and a transverse passage connected to the axle passage to direct the lubricant to a bearing mounted outwardly of the axle bolt. Fittings have been provided to receive the lubricant and to prevent it from flowing out of the axle passage before being delivered to the transverse passage.
A problem heretofore associated with such prior art axle bolts has been that the fittings had a tendency to be loosened and even broken off during use of the axle bolt. When that happens the fitting must be tightened or replaced before the axle bolt can be used to lubricate the bearing.
The present invention provides a simple means for permitting lubrication of the bearings without requiring additional and complicating structures. Close tolerances are provided between the fitting and the hole formed in the axle bolt to receive the fitting. This as well as the means provided to protect the fitting mounted to the axle bolt prevent it from being loosened or broken.
This is accomplished by providing an axial passage in the axle bolt which communicates with a lubrication fitting such as a ZERK grease fitting in the cap of the axle bolt and with a transverse passage at the end opposite the ZERK grease fitting. The ZERK grease fitting is mounted in a conical recess formed in the head of the bolt. In this way it is protected and the danger of it being accidentally loosened or broken is substantially diminished.
Lubrication provided at the ZERK grease fitting is transmitted through the axial passage to the transverse passage to the exterior of the axle bolt to lubricate the bearings or the like carried by the axle bolt.